Explosive cartridge and method of loading high explosives in drill holes



June 10, 1930. Q NIESEN 1,763,407

EXPLOSIV E CARTRIDGE AND METHOD OF LOADING HIGH EXPLOSIVES IN DRILL HOLES Filed May 6, 1925 X ll .5

\ j 5 he H5507- 6f Patented June 10, 1930 UNITED STATES PATENT OFFICE.

OTTO IB. NIESEN,- or nnnnmowu, rnmvsnvmm, AssIeNonro TROJAN rownnn COMPANY, or NEW YORK; 11.- Y.,

A CORPORATION NEW YORK ExrLosr-vn cen'rnrnon AND mnrnon or roanm'e men nxrnosrvns m mum, HOLES Application filed Bay 0, 1925. Serial No. 28,861.

The principal object of this invention is to provide a novel cartridge so constructed as to materially facilitate the proper loading of vide a novel method by means of which charges of high explosives may be loaded in drill holes rapidly, efiiciently and with safety, even where such holes are partly or wholly filled with water or have rough and irregular side walls.-

' The invention resides in certain novel details of construction as hereinafter fully set forth and as illustrated in the attached drawing. which illustrates in perspective a cartridge made in accordance with my invention.

It is customary in loading drill holes with cartridges of the larger sizes, and particularly when explosives of relatively low sensitiveness and relatively high safety are used, to drop the explosives down the drill hole, the paper shell or wrappings surrounding the explosive being ruptured when the cartridge strikes the bottom of the hole or the top of a cartridge previously inserted. While this method of loading has proven particularly effective and satisfactory in loading dry or relatively dry holes and where the drill hole is sufliciently smooth and straight, it cannot be relied upon t0 give satisfactory results where the bore or drill hole to be loaded is even partly filled with water or where the sides of the holes-are rough or uneven, as is often the case .even in the most carefully v drilled holes, and particularly in certain rock formations. Where the rough or uneven sides of the hole do not permit the use of the drop method. itis necessary to employ cartridges materially smaller in diameter than the diameter of the drill hole, which is objectionable,

since the best results in loading as well as the results 1n subsequent blasting are obtamed when the cartridge diameter approximates as nearly as is compatible with loading practice, the diameter of the drill hole in which the charge is to beloaded. Where the hole is partly filled with water, the impact of the falling shell againstthe surface of the water in the hole leads to the rupture of the cartridge at a oint which may be quite distant from the ottom of the-hole, and since the cartridge when so ruptured does not refd- I ily sink through the water to the bottom of the hole, the method of loading holes partly filled with water by dropping does not perf mit the explosive charge to be properly placed in the hole, and does not give the desired blasting results. Where the holes are entirely filled with water, the dropping method is also unsatisfacto By my present invention, as hereinafter set forth,it is possible to load within wet holes and within dry holes of rough or irregular outline, cartridges of larger diameter than is possible by other methods of loading now known and without the rupture of the protecting waterproofing envelope of the cartridge during the loading'operation. By retaining intact this waterproofing envelope, deterioration of the cartridge by absorption of moisture or actually of water by the explosive in wet holes is avoided.

I have discovered that by providing a cartridge of explosive with a suitable harness whereby the cartridge may belowered controllably through the hole as hereinafter more fully described. I am able both to safely and rapidly load explosives in drill holes containing water or having rough or irregular surface, and even in drill holes departing from circular cross section under conditions that represent extremely diflicult loading by other methods heretofore employed. In the as the cartridges do not readily sink to the ottom of the hole.

preferred form, the said harness consists of a transverse positioning members are also provided which function to retain the said longitudinal members in proper position during manufacture, transportation and use.

With reference to the drawing, indicates a cartridge of any suitable explosive, and 2 the aforesaid tension members extending longitudinally with relation to the cartridge 1 and preferably crossing and being mutually reinforced at the bottom of the cartridge. At a point above the cartridge, these members may be fastened together in any suitable manner. In order to retain'these members in their proper relative positions and to prevent displacement, I provide in the present instance two transverse positioning members 3 in the form of paper rings passing around the cartridge to which the tension members are secured either by adhesive or other suitable means.

Although I prefer to employ four tension members in' the ordinary application of my invention, I may use a smaller or greater number. Theessential factor as regards the tension members is that they shall be of suf-' ficient strength to enable suspension of the cartridge during the loading operation while permitting the separation, preferably by breakage, of the cartridge from a loading cord or cable by means of which the cartridge is lowered into the drill hole. Such a cord I have illustrated in the drawing as attached to the tops of the tension members and designated by the reference numeral 4.

Although a hook or other formof attaching device may be employed in connecting the loading cord 4 to the tension members, no special arrangement is required for the purpose, since the tension members may be attached directly to the rope or cable or may be looped or tied over a knot in the rope or cable, or over any crosswise member attached to or forming a part of the cable. Instead of the transverse supporting members 3 completely surrounding the cartridge, the longitudinal tension members may be heldin posi; tion in many other ways, as by a number of small stickers or other supporting means, and the members may be made to adhere directly to the body of the cartridge by dipping the entire cartridge, after applying the harness, in any suitable cementing or attach-' ing medium. In this latter case, the transverse retaining members may be eliminated. It may be desirable, for example, to dip the cartridge and its-loading harness or bridle in paraiiin Wax or other Waterproofing or cementing agent. instead of longitudinal members of string or cord, I may employ members of thin wire or strips ofpaper, either plain or twisted, or strips of cloth. As to the composition and disposition of the longitudinal members and the method of securing these members to the cartridge, I do not wish to be limited in View of the wide choice that is offered.

Under special conditions, the use of glue or other cementing agent may be avoided by sewing or stitching the tension members to the body of the cartridge, and the tension members may also form a part of the water- It will also be evident that proofing envelope of the cartridge, being attached to such envelope at the time that it is made. In general, however, I prefer to make the cartridge in the usual manner and of the usual diameter and length completely loaded with the desired explosive, and to thereafter apply the tension members either mechanically or by hand to such cartridge,

preferably while the said members are extended or under tension, this method facilitating the desirable positioning of the members with respect both to the cartridge and to each other.

The procedure of loading cartridges made in accordance with the aforedescribed invention may be as follows: After first attaching the longitudinal or tension members of the cartridge to a suitable loading cord, rope or other member, the cartridge is lowered at any desired rate into the hole until the cartridge is partly seated in the bottom of the latter or on top of a cartridge previously inserted, or until the cartridge has been placed at any desired point'in the hole. By then giving the rope or cord a slight jerk or quick upward pull, I rupture the longitudinal tension members and free the cartridge from its attachment to the loading cord or rope. Obviously it will be essential under these circumstances that the tension members be of such strength that while supporting the entire weight of the cartridge under static conditions and even under such conditions of movement and jerking as are incident to the lowering of the cartridge in the hole, they must be sufliciently weak to break when subjected to the stress resulting from the inertia of the cartridge to a rapid jerk or pull. It should further be noted that thelongitudinal tension members preferably are so attached to the exterior of the waterproofing membrane or envelope of the cartridge as to involve no rupture of this envelope upon the rupture of the tension members, as previously described, the invention thus enabling the cartridge being placed at any desired location within the length of the drill or bore hole and the release of the cartridge from the lowering rope, cord or cable without damage to the waterproofing character of the surrounding cartridge envelope and with the envelope in wholly undamaged condition.

I have found that in practice the pull required to rupture the tension members 'by means of a quick upward jerk is only slightly greater than the breaking strength of a single one of the tension members, since the latter apparently break individually and do not collectively resist breakage, as is the case when the cartridge is lowered or raised in the hole and when the stresses among the tension members are equalized by positionin movements permitted by the form of the arness. It may, however, be desirable to employ one or more tension members of difierent material than the othersand adapted to break in advance of the others when the detaching pull or jerk is given.

As previously stated, the device is capable of large modification without'departure from the essential features of the invention, and I do not wish to be limited in any sense to the form of the device herein described and illustrated.

I claim: l 1. An improved cartridge comprising a charge of explosive, an envelope surrounding same, and a plurality of rupturable tension members exterior to the cartridge envelope to which a lowering member may be attached and which are adapted to rupture as a result gf a sharp upward pull on the lowering mem- 2. An improved cartridge comprising a charge of explosive, an envelope surrounding same,,a plurality of rupturable tension members arranged longitudinally with respect to the length of the cartridge, and at least one transverse positioning member attached the tension members and to the cartridge.

3. The process of loading cartridges in drill holes, which consists in providing the.

. cartridge with a rupturable element, suspending the cartridge from the rupturable element, attach in said element to a member s by means of whic the cartridge may be lowered into the drill hole, and rupturing the said element after the desired location of the cartridge by a sharp upward pull of the lowering member.

' 4. The process of loading cartridges in drill holes, which consists in attaching the L the cartridge, said member including a relacartridgeto a member adapted for lowering tively easily rupturable section, lowering the cartridge into the drill hole, and exerting a sharp upward pull upon the lowering member sufficient to,rupture the said relatively weak section.-

A OTTO B. NIESEN. 

